1. Field of the Invention
The present invention relates generally to a tissue-stimulating prosthesis and, more particularly, to an electrode carrier member for such a prosthesis.
2. Related Art
Delivery of electrical stimulation to appropriate locations within the body may be used for a variety of purposes. For example, function electrical stimulation (FES) systems may be used to deliver electrical pulses to certain muscles of a recipient to cause a controlled movement of the limb of such a recipient.
As another example, electrical stimulation of the cochlea using cochlear implant systems may also be used to directly deliver electrical stimulation to the auditory nerve fibers, thereby allowing the brain to perceive a hearing sensation resembling the natural hearing sensation normally delivered to the auditory nerve.
Cochlear implant systems typically have two primary components: an external component commonly referred to as a control unit, and an implanted component commonly referred to as a receiver/stimulator unit. Traditionally, both of these components cooperate with each other together to provide the sound sensation to a recipient.
The external component has traditionally included a microphone that detects sounds, such as speech and environmental sounds, a speech processor that selects and converts certain detected sounds, particularly speech, into a coded signal, a power source such as a battery, and an external transmitter antenna.
The coded signal output by the speech processor is transmitted transcutaneously to the implanted receiver/stimulator unit located within a recess of the temporal bone of the recipient. This transcutaneous transmission occurs via the external transmitter antenna which is positioned to communicate with an implanted receiver antenna provided with the receiver/stimulator unit. This communication transmits the coded sound signal while also providing power to the implanted receiver/stimulator unit. Conventionally, this link has been in the form of a radio frequency (RF) link, but other such links have been proposed and implemented with varying degrees of success.
The implanted receiver/stimulator unit traditionally includes the noted receiver antenna that receives the coded signal and power from the external processor component. The implanted unit also includes a stimulator that processes the coded signal and outputs a stimulation signal to an intracochlear electrode assembly mounted to a carrier member which applies the electrical stimulation directly to the auditory nerve producing a hearing sensation corresponding to the original detected sound.
To position the carrier member that is mounting the electrode assembly, a surgeon typically forms a cochleostomy before gripping the member by hand or with a tool and then inserting a leading end of the carrier member through the cochleostomy and into preferably the scala tympani of the cochlea.
One potential problem during the insertion process is the potential for the carrier member to be damaged and/or rendered at least partially inoperative due to the handling the member receives prior to and during the insertion procedure.